Valence-dependent changes in visual arousing elicitation: an exploratory study in EEG gamma oscillations

Area of Science:

• Neuroscience
• Cognitive Psychology
• Affective Science

Background:

• Emotion regulation involves key brain regions like the prefrontal cortex, amygdala, and insular cortex.
• Understanding how arousal levels modulate brain dynamics during valence-specific emotional processing remains incomplete.

Purpose of the Study:

• To investigate the impact of varying arousal levels on brain activity during pleasant and unpleasant emotional elicitation.
• To explore changes in electroencephalography (EEG) power spectra and functional connectivity related to emotional valence and arousal.

Main Methods:

• A preliminary study utilizing electroencephalography (EEG) with 22 healthy subjects.
• Stimulation via affective pictures from the International Affective Picture System across four arousal levels and two valence levels (pleasant/unpleasant).
• Analysis focused on gamma oscillations (> 32 Hz) and functional connectivity patterns.

Main Results:

• No significant changes in pleasant versus unpleasant elicitation were observed at low or high arousal levels.
• Valence-dependent changes in brain activity were detected in prefrontal and occipital regions during intermediate arousal.
• Pleasant stimuli modulated short-range connectivity (right hemisphere), while unpleasant stimuli affected medium-range connectivity (left hemisphere) across arousal levels.

Conclusions:

• Arousal level is a critical factor influencing how the brain processes emotional valence.
• Intermediate arousal levels are particularly sensitive to valence-induced changes in neural activity and connectivity.
• Hemispheric and range-specific connectivity patterns differentiate responses to pleasant and unpleasant stimuli under varying arousal conditions.